Vulcanization systems comprising sulfur and an alkali metal salt of an organic carboxylic acid, hereinafter referred to as a soap and sulfur cure system, were originally disclosed and claimed in U.S. Pat. No. 3,458,461 issued on July 29, 1969 to F. F. Mihal. This soap and sulfur cure system provided better mold release, reduced corrosion of molds, better economy, freedom from offensive fumes and vapors, optional elimination of post-curing and excellent bin stability.
An improvement in the soap and sulfur cure system was disclosed in U.S. Pat. No. 3,506,624 issued on Apr. 14, 1970 to R. A. Behrens. The improvement comprised the utilization of a combination of sulfur, an alkali metal salt of an organic carboxylic acid and an N-substituted -mono or bis-maleimide. This system provided the additional advantages of improved processing safety and good cure rate.
The present invention represents the culmination of a long series of investigations conducted largely by the inventor and his associates directed to improving the soap and sulfur cure system.
Accordingly, it is a primary object of this invention to provide a new and improved soap and sulfur cure system for vulcanizing particular synthetic elastomeric polymers. Another object of this invention is to provide a soap and sulfur cure system which has a faster cure rate.
Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by the practice of the invention, the objects and advantages being realized and attained by means of compositions and improvements, particularly pointed out in the appended claims.